两种培育钻石的制造方法——HPHT高温高压法，以及后来新的CVD化学气相沉积法。所以这一次我们将从制造方法作为切入口，带领大家一起，对两种培育钻石工艺进行简单的探讨，看看两种制造方法是如何一步步蜕变为成熟的技术。

在1797年，英国科学家Smithson Tennant证明了一个观点：钻石只是由纯碳极为紧密地结合而成。在此之后，各国研究人员就在不断地投入科研力量，希望早日在实验室里就能造出同样紧密的碳原子合成结构。

很多人都知道，钻石就是极为纯净的碳。同样的，石墨也是纯净的碳，但是因为石墨的碳原子结构松散，而钻石的原子结构极为紧密，这才让钻石不仅有稳定的化学性质，还有极为坚硬的物理性质。

Manufacturing Methods of Lab-Grown Diamonds — HPHT (High-Pressure High-Temperature) and the Later-developed CVD (Chemical Vapor Deposition)

In 1797, British scientist Smithson Tennant proved a key point: diamonds are simply composed of pure carbon atoms bonded extremely tightly together. Since then, researchers from various countries have continuously invested in scientific research efforts, hoping to replicate this highly compact carbon atomic structure in laboratories as soon as possible.

As most people know, diamonds are made of extremely pure carbon. Similarly, graphite is also composed of pure carbon. However, due to the loose atomic structure of graphite and the extremely dense atomic structure of diamonds, diamonds possess not only stable chemical properties but also exceptional physical hardness.

HPHT高温高压合成法     HPHT (High-Pressure High-Temperature) Synthesis Method

HPHT是模拟钻石生长环境，是最传统的钻石合成的方法。其方法是将一颗晶种和金属助溶剂放入机器装置内的一个小舱室。

HPHT, which simulates the natural diamond growth environment, is the most traditional method for synthesizing diamonds. The process involves placing a diamond seed crystal and a metal solvent into a small chamber within specialized equipment.

紧接着再控制其舱室内的温度和压力，让其达到两千摄氏度以上以及103.4亿帕每平方英尺的压力。在这样的高温高压下，钻石的粉末原料溶解在熔化的金属助溶剂中，然后在钻石晶种上结晶，形成合成钻石晶体。

Subsequently, the temperature and pressure inside the chamber are precisely controlled to exceed 2,000 degrees Celsius and reach 10.34 gigapascals (equivalent to 103.4×10⁸ pascals per square foot). Under such extreme high-temperature and high-pressure conditions, the diamond powder raw material dissolves in the molten metal solvent and then crystallizes onto the diamond seed crystal, forming a synthetic diamond crystal.

大约几周或一个月的时间后，取出之前放入的组装块   After approximately several weeks or one month, the pre-assembled block placed inside the chamber is removed.

组装块取出后的样子如下    The appearance of the assembled block after removal is as follows.

再进行电解提纯出来以后的钻石晶体  The diamond crystal is then extracted through electrolytic purification.

然后就可以得到典型的HPHT钻石毛坯  This yields a typical HPHT diamond rough.

再进行切割后，就是大家平时看到的HPHT钻石了  After the cutting and polishing process, it becomes the HPHT diamond that people commonly see in the market.

这种合成方法模拟钻石的高温高压生长环境，当然其温度压力与时间达不到天然钻石的生长时间，由此形成的钻石晶体结构和天然钻石还是有一定区别的——HPHT的结构是立方八面体，而钻石则多是八面体。

从前，HPHT产出的钻石为小克拉钻石（尤其是钻石厘石），且颜色偏白发灰。但如今，随着技术进步，全球范围内，一些公司已经可以制造出超过十克拉的HPHT钻石了，并且颜色净度都极好。

This synthesis method mimics the high-temperature and high-pressure conditions of natural diamond formation. However, the temperature, pressure, and duration involved cannot match the extremely long growth period of natural diamonds. As a result, there are certain differences between the crystal structure of HPHT diamonds and natural diamonds: HPHT diamonds typically have a cuboctahedral structure, while natural diamonds mostly exhibit an octahedral structure.

CVD化学气相沉积法     CVD (Chemical Vapor Deposition) Method

CVD化学气相沉淀法，它是近年来新兴的合成方法，相比于HPHT高温高压法，它需要的是高温低压的环境。CVD, or Chemical Vapor Deposition, is an emerging synthetic method developed in recent years. In contrast to the HPHT method, it requires a high-temperature and low-pressure environment.

首先，将一个种晶盘放入充满含碳氢气体的真空室，比如甲烷气体。First, a diamond seed crystal plate is placed into a vacuum chamber filled with hydrocarbon gases, such as methane.

然后用一种微波等离子能量源穿透这种气体，让其气体的分子分解，碳原子被吸附到下方钻石晶种盘里。目前它的增长速率在0.2mm每小时。具体能产出多少取决于真空室的大小和种晶盘大小。Then, a microwave plasma energy source is used to ionize the gas, breaking down its molecular structure. Carbon atoms are then adsorbed onto the surface of the diamond seed crystal plate below. Currently, the growth rate of CVD diamonds is around 0.2 millimeters per hour. The final output volume depends on the size of the vacuum chamber and the seed crystal plate.

一般来讲，数周的时间可以生成一批CVD钻石毛坯，为板状晶体物 Generally speaking, a batch of CVD diamond rough, which takes the form of plate-shaped crystals, can be produced within several weeks.

然后再经过打磨，将附着的黑色石墨边缘去掉露出钻石的无色晶体 Through the polishing process, the attached black graphite edges are removed, revealing the colorless diamond crystal underneath.

再经过打磨，便从一片晶种变成了一颗钻石  After further cutting and polishing, a single seed crystal plate is transformed into finished diamonds.

就这样，一颗颗宝石级的CVD钻石便出世了    In this way, gem-quality CVD diamonds are produced.

是不是感叹科技的神奇呢？   Is it not amazing to witness such remarkable technological feats?

HPHT/CVD钻石的区别

CVD钻石合成法能够成功将培育钻石市场推向新的领域，是因为以下几点：

1.可以改变钻石颜色

天然钻石的颜色，也是因为在生长过程中通过大自然其它元素的加入而改变，有些也是因为晶体结构缺陷导致。例如，黄色钻石是因为生长过程中受氮元素影响而变色，蓝色有可能是因为硼元素，绿色则是因为放射线使晶体结构中的碳原子偏离正常位置所导致。

而CVD钻石在其种晶盘的生长过程中，在碳氢化合物气体中加入致色元素，便可以改变宝石的颜色。目前，大克拉的粉钻蓝钻黄钻已经问世，有一些颜色非常好，甚至GIA在报告中也称其为Fancy Intense（艳丽浓郁）或者Fancy（艳丽）的级别。

Differences Between HPHT and CVD Diamonds

The CVD diamond synthesis method has successfully propelled the lab-grown diamond market into a new era, primarily due to the following key advantages:

1. Tunable Diamond Color

2.CVD钻石内部更加纯净

在前文我们已经介绍过，CVD钻石的制造方法，因为其生长环境更多的是用气体，而不是像HPHT钻石加入了金属助溶剂，CVD钻石最大的优势就是内部非常纯净。净度一般在VVS1-SI1,大部分都可在VS2以上。

这里我们需要科普一些专业知识，钻石分为四种类型，分别是Type IaA(原子结构里含有氮元素)，Type Ib（含有不规则排列的氮元素），Type IIa(纯净碳元素)，Type IIb(含有硼元素，一般的蓝色钻石的致色原因)

2. Higher Internal Purity

As mentioned earlier, the CVD manufacturing process utilizes gas as the primary carbon source, unlike the HPHT method which relies on metal solvents. This gives CVD diamonds a significant advantage: exceptional internal purity. Their clarity grades typically range from VVS1 to SI1, with the majority falling above VS2.

四种类型中，天然钻石里Type IIa全都是碳原子组成，是最纯净的，也是最稀有的，天然钻石里的Type IIa钻石的净度和颜色一般都极好，卖价也是最高的。

而CVD钻石最难得的是，所有的CVD钻石几乎都是Type IIa,这就注定了它被制造出来就是和天然钻石媲美的。这就是为什么CVD钻石普遍质量都比天然钻石更好。

CVD钻石的问世，之所以给钻石界带来巨大震动，最大的原因就是因为其纯净的内部。如果说HPHT钻石内部还有一些证据的话，CVD钻石可以完全抹去其人造的“证据”。

CVD钻石内部纯净，如果吹毛求疵，内含物也都是一些高等级天然钻石里的有的pinpoints（极小的黑色点）。光从显微镜下已经极其难辨认其差别，目前全世界能权威检测CVD钻石的两家机构分别是GIA（美国宝石学院）以及IGI（国际宝石学院）。

Among these four types, natural Type IIa diamonds, composed purely of carbon atoms, are the rarest and most pristine. They usually exhibit superior clarity and color, commanding the highest market prices.

What makes CVD diamonds particularly remarkable is that nearly all CVD diamonds are classified as Type IIa. This inherent characteristic ensures that CVD diamonds are comparable in quality to the finest natural diamonds, explaining why CVD diamonds generally boast better quality than many natural diamonds.

The emergence of CVD diamonds has sent shockwaves through the diamond industry, largely due to their exceptional internal purity. While HPHT diamonds often retain subtle traces of their synthetic origin, CVD diamonds can be produced with almost no visible artificial characteristics.

内部纯净的CVD钻石，自然光下拍摄 CVD diamond with high internal purity, photographed under natural light.

需要注意的是，随着CVD钻石的横空出世，很多不法商人购买很多大克拉CVD钻石送到小检测站去做天然钻石的证书然后卖出天然钻石同等的价格，请读者们在买钻石时一定要小心，不要花冤枉钱。It is important to note that with the rise of CVD diamonds, some unscrupulous merchants have purchased large-carat CVD diamonds and obtained counterfeit natural diamond certificates from unregulated testing labs, then sold them at prices equivalent to natural diamonds. Therefore, readers are advised to exercise extreme caution when purchasing diamonds to avoid falling victim to such scams and wasting money.

3.HPHT钻石的优势，颜色    

HPHT钻石的技术其实也一直在更新换代，从前HPHT只专注于造一些比较小的宝石级钻石，但是近年来，许多HPHT钻石制造公司也开始制造大克拉钻石，有一些甚至超过十克拉。

HPHT钻石现在也可以做到内部纯净到达VVS级别。相比CVD钻石，它最大的优势便是颜色级别很高，例如HPHT钻石许多都可以达到DEF（白色钻石颜色的最高三个级别）。

从前HPHT的颜色白得发灰，而现在更多的可以达到标准的DEF色。但HPHT的金刚光泽确实不比CVD钻石优秀，金刚光泽通常是因为超高的折射率和良好的切磨工艺导致——是宝石界里透明宝石能呈现的最明锐的一种光泽。毫无疑问，钻石的金刚光泽是最优秀的。CVD钻石的金刚光泽已经完全可以媲美天然钻石，HPHT相比较下稍显逊色。所以大部分珠宝界会用HPHT钻石作为厘石，因为它颜色非常优秀，作为小厘石明亮又闪烁，非常完美。

3. Advantages of HPHT Diamonds: Color Quality

HPHT technology has also been continuously updated and upgraded over time. In the past, HPHT was primarily focused on producing small gem-quality diamonds, but in recent years, many HPHT diamond manufacturers have started producing large-carat diamonds, some even exceeding 10 carats.

Modern HPHT diamonds can also achieve impressive internal purity, reaching VVS grades. Compared with CVD diamonds, their biggest advantage lies in their high color grades—for instance, many HPHT diamonds can attain the top three color grades in the white diamond scale: D, E, and F.

不论是HPTP还是CVD钻石，我们不仅见证着其制造工艺的日趋成熟。我们也在思考，当科技发展逐渐触碰到“巧夺天工”这个看上去触不可及的概念，当“天然”与“人造”的界限被冲刷模糊，我们作为消费者，是否也应当追上时代的脚步，到更加包容纷繁的世界里看看呢？

我们有足够的理由相信，在未来，HPTP和CVD钻石将大放异彩。这是源自百年科技钻研所带来的自信，同时也对新时代探索者抱有极大的期待和信心。我希望能看到未来的某一天，HPTP和CVD钻石周围簇拥着的不再是偏见和冷落，它们吸引着不同的需求和相同的称赞，受到大家同等的喜爱和追求。

Whether it is HPHT or CVD diamonds, we have witnessed the continuous maturation of their manufacturing processes. At the same time, we are prompted to reflect: as technological development gradually approaches the seemingly unattainable concept of "rivaling nature’s craftsmanship" and the boundary between "natural" and "lab-grown" becomes increasingly blurred, should we as consumers keep pace with the times and embrace this diverse and inclusive world?

文章来源：搜狐网